Generally, a washing machine refers to an apparatus capable of washing and drying laundry, including the concepts of a washer, a dryer, and a combined washer and dryer.
The dryer, as an apparatus to dry washed laundry using hot air, may be classified into an exhausting type dryer and a condensing type (circulating type) dryer.
The condensing type dryer is structured to circulate hot and dry air through a receiving part storing laundry, to thereby dry the laundry. More specifically, the condensing type dryer dries the laundry through processes of supplying the hot and dry air into the receiving part, performing heat exchange between the hot and dry air and the laundry, condensing humid air having undergone the heat exchange, and heating the condensed air and resupplying the heated air to the receiving part.
Meanwhile, the exhausting type dryer also supplies hot air into the receiving part storing laundry but, however, discards the air heat-exchanged with the laundry to the outside. To this end, the exhausting type dryer includes a device to heat the air being supplied to the receiving part, a supply path to supply the heated air to the receiving part therethrough, and an exhaust path to exhaust the heat-exchanged air to the outside of the receiving part.
The exhausting type dryer has generally been applied to a washing machine since it has a relatively simple structure compared to the condensing type dryer. However, the exhausting type dryer is not able to recycle heat remaining in the humid air being exhausted through the exhaust path.